TWI447163B - Novel polythiophene-polyanion complexes in nonpolar organic solvents - Google Patents

Description

Novel polythiophene-polyanion complexes in non-polar organic solvents

This invention relates to novel polythiophene-polyanion complexes which are soluble or dispersible in non-polar organic solvents, and uses thereof.

Conductive polymers are gaining increasing economic importance because polymers are superior to metals in terms of processability, weight, and performance control through chemical modification. Examples of conventional π-conjugated polymers are: polypyrrole, polythiophene, polyaniline, polyacetylene, polyphenylene, and poly(p-phenylene-vinyl). The conductive polymer layer has various industrial uses, for example, as a counter electrode for polymerization in a capacitor, or as a through joint of a printed circuit board. The conductive polymer is derived from a precursor of a monomer, such as an optionally substituted thiophene, pyrrole, and aniline, and individual derivatives thereof, which may be oligomers by chemical or electrochemical oxidation. preparation. Chemically oxidative polymerization is common because it is technically readily accomplished on a liquid medium and on a variety of substrates.

A particularly important and industrially useful polythiophene is poly(extended ethyl-3,4-dioxythiophene) (PEDOT or PEDT), for example: described in EP 339 340 A2, which is chemically polymerized to extend It is prepared by benzyl-3,4-dioxythiophene (EDOT or EDT) and has a very high conductivity in the oxidized form. Many poly(alkyl-3,4-dioxythiophene) derivatives, especially poly(extended ethyl-3,4-dioxythiophene) derivatives, and their monomer units, synthesis reactions, and applications are reviewed L. Groenendaal, F. Jonas, D. Freitag, H. Pielartzik and JR Reynolds, Adv. Mater., No. 12 (2000), pp. 481-494.

Dispersions of PEDOT and polystyrenesulfonic acid (PSS) are of particular industrial importance, as disclosed, for example, in EP 0 440 957 B1. Transparent conductive films are obtained from these dispersions, and many applications have been found, for example, as an antistatic coating or as a hole injection layer in an organic light emitting diode.

EDT is polymerized in a PSS aqueous solution to form a PEDT/PSS complex. Cationic polythiophenes, which comprise a polymerized anion as a relative ion for charge compensation, are also commonly referred to in the art as polythiophene/polyanion complexes. Due to the polymer electrolyte properties of PEDT as a polycation and PSS as a polyanion, this complex is not a true solution, but it is a dispersion. The extent to which the polymer or part of the polymer is dissolved or dispersed depends on the mass ratio of the polycation to the polyanion, the charge density of the polymer, the salt concentration of the environment, and the properties of the surrounding medium (V). .Kabanov, Review of Soviet Chemistry, 74th, 2005, pp. 3-20). This transition can be fluid, so there is no distinction between the words "dispersed" and "dissolved". Similarly, no distinction is made between "dispersion" and "solution" or between "dispersant" and "solvent". Instead, these words are used in an equivalent manner.

In the prior art, it has heretofore been possible to prepare polythiophene-polyanion complexes only in polar solvents. EP 0 440 957-A2 describes a process for the preparation of polythiophene-polyanion complexes which can only be carried out in very polar solvents, as exemplified by the polyanions, polystyrenesulfonic acid and poly(meth)acrylic acid, only It can be dissolved in polar solvents such as water or lower alcohols. The polymerization of PEDT only in water is specifically described. One disadvantage of this method is that the choice of solvent is limited to polar solvents, i.e., non-polar solvents cannot be used in the preparation of this polythiophene-polyanion complex.

EP 1 373 356 B1 and WO 2003/048228 describe the preparation of polythiophene-polyanion complexes in anhydrous or low water solvents. In this case, the aqueous solvent was replaced by another water-miscible organic solvent. For this, the water is removed by, for example, distillation after the addition of the second solvent. This procedure has the disadvantage that a two-stage procedure must be used due to the distillation. Furthermore, the solvent added must be water-miscible, which likewise results in a limited polar solvent.

A method is described in JP 2005-068166, in which a conductive polymer, such as PEDOT, is first dried and subsequently dispersed in an organic solvent. The organic solvents mentioned are especially those having a dielectric constant of 5 or more. Examples are indicated as isopropanol and gamma-butyrolactone. This method also has the disadvantage that it requires re-dissolution using a polar solvent. Another disadvantage of this method is that the conductive polymer must first be synthesized and then redispersed. Otani et al. did not disclose any polythiophene-polyanion complexes.

In 2002, H. Okamura et al. (Polymer 2002, No. 43, pp. 3155 to 3162) describe the synthesis of a block copolymer of styrene and styrene sulfonic acid. The ratio of the two comonomers was changed, and the copolymer was found to be soluble in tetrahydrofuran, chloroform, acetone, dimethylformamide, methanol, and water. However, the copolymer has not been found to have any solubility in aliphatic or aromatic hydrocarbons such as hexane, toluene, or benzene. No complex compounds were prepared using any conductive polymer, such as polythiophene/polyanion complexes, and the conductivity or electrical resistance of the film was not investigated. Thus the polymers described by Okamura et al. are not suitable for use in confirming the solubility of polymer complexes in very non-polar solvents such as toluene.

A series of studies also describe how to achieve the solubility of polythiophenes by attaching pendant groups to thiophene monomers, followed by polymerization, or by preparing a block of thiophene units and units to enhance solubility. Copolymer.

For example, Luebben et al., Polymer Materials: Science & Engineering 2004, No. 91, page 979: Preparation of a block copolymer of PEDOT and polyethylene glycol. The relative ions used herein are perchlorate and p-toluenesulfonic acid. The polymer is dissolved in a polar organic solvent such as propyl carbonate and nitromethane and has a conductivity of 10 ^-4 S/cm to 1 S/cm. However, this block copolymer has the disadvantage that it is only soluble in very polar solvents. In addition, the selected counter ions are not involved in the formation of the film, so the conductive film cannot be formed using these block copolymers.

Other publications describe the preparation of an organopolythiophene solution which enhances solubility by introducing pendant groups to the thiophene. For example, Yamamoto et al., Polymers, No. 43, 2002, pp. 711-719, describe the preparation of a hexyl derivative of PEDOT, which is an uncharged molecule that is soluble in an organic solvent. The addition or iodine oxidation reaction is also described. However, it is not indicated whether or not the conductive film can be prepared from the thiophene organic solution which is doped or oxidized. Another disadvantage of this method is that the molecular weight of the polymer is low, and thus the film formation properties are not good. In the previously cited publication, the molecular weight (M _w ) is up to 2400 g/m and 8500 g/m. Since polythiophene acts as both a film-forming polymer and a conductive polymer, these two properties cannot be independently constructed. In principle, this method has the disadvantage that the introduction of pendant groups onto the thiophene not only affects the solubility properties but also the electronic properties of the molecules.

Therefore, there is a need for a dispersion of conductive polythiophene in a non-polar solvent, whereby a conductive film can be obtained. This need is based on the fact that such dispersions have hitherto only been found in very polar solvents. More particularly, there is a need for a dispersion in a non-polar solvent which has good film-forming properties and exhibits electrical conductivity. Because many coating systems are based on non-polar solvents, there is a great need for conductive polythiophenes that can be dissolved or dispersed in non-polar solvents.

It is therefore an object of the present invention to prepare a dispersion of polythiophene which is soluble in a non-polar solvent and from which a conductive film can be produced. Another object of the present invention is to prepare such a dispersion, and the solvent used in the synthesis is also the solvent of the final dispersion, so that no replacement solvent is required.

It has now surprisingly been found that a complex of an optionally substituted polythiophene and a polyanion comprising a copolymer solves this problem.

The present invention therefore provides a complex comprising an optionally substituted polythiophene and a polyanion, characterized in that the polyanion comprises a copolymer having repeating units of the formulae (I) and (II), Or a repeating unit of the formulae (I) and (III), or a repeating unit of the formulae (II) and (III), or a repeating unit of the formula (I), (II) and (III):

Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ are each independently H, an optionally substituted C ₁ -C ₁₈ -alkyl group, and an optionally substituted C ₁ -C ₁₈ - alkoxy groups, optionally substituted with one of C ₅ -C ₁₂ - cycloalkyl radical, optionally substituted with one of C ₆ -C ₁₄ - aryl radical, optionally substituted with a a substituted C ₇ -C ₁₈ -aralkyl group, an optionally substituted C ₁ -C ₄ -hydroxyalkyl group or a hydroxyl group, preferably H, and R ⁶ is H, or a An optionally substituted C ₁ -C ₃₀ -alkyl group, preferably a C ₂ -C ₁₈ -alkyl group, D is a direct covalent bond or an optionally substituted C ₁ - a C ₅ -alkylene group, R is a linear or branched, optionally substituted C ₁ -C ₁₈ -alkyl group, an optionally substituted C ₅ -C ₁₂ -cycloalkyl group a optionally substituted C ₆ -C ₁₄ -aryl group, an optionally substituted C ₇ -C ₁₈ -aralkyl group, an optionally substituted C ₁ -C _{a 4} -hydroxyalkyl group or a monohydroxy group, preferably H, x is an integer from 0 to 4, preferably 0, 1 or 2, more preferably 0 or 1, and M H, or Li ⁺ , Na ⁺ Preferably, H ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , NH ₄ ⁺ , Na ⁺ , K ⁺ , or other cations.

The general formula (II) should be understood that the substituent R can be bonded to the aromatic ring x times.

In a preferred embodiment of the invention, the polyanion of the complex is a copolymer of repeating units of formula (II) and (III).

In an even more preferred embodiment of the invention, the polyanion is a copolymer of repeating units of formula (IIa) and (III)

Wherein R ⁵ is H or an optionally substituted C ₁ -C ₁₈ -alkyl group, preferably H or an optionally substituted C ₁ -C ₆ -alkyl group, A radical or H is more preferred, preferably H, and R ⁶ is H or an optionally substituted C ₁ -C ₃₀ -alkyl group, optionally substituted C ₁ - A C ₂₀ -alkyl group is preferred, and an optionally substituted C ₁ -C ₁₂ -alkyl group is more preferred.

The proportions of the repeating units of the formula (I), (II) and (III) in the monolithic polymer are a, b and c, respectively, and a, b and c are mass percentages between 0 and 100%. a and b are preferably between 0 and 50%, wherein a and b must not be both 0%. The ratio of c is preferably between 20 and 100%.

In the present specification, C ₁ -C ₁₈ -alkyl represents a linear or branched C ₁ -C ₁₈ -alkyl group, for example: methyl, ethyl, n- or i-propyl, n-, i- , secondary-, or tertiary-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylpropyl, 1,1-dimethyl Propyl, 1,2-dimethylpropyl, 2,2-di-methylpropyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-decyl, Ortho-indenyl, n-octadecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, n-hexadecyl, or n-octadecyl; C ₁ -C ₃₀ -alkyl represents a linear or branched C ₁ -C ₃₀ -alkyl group, together with the aforementioned C ₁ -C ₁₈ -alkyl group, including alkyl groups such as n-nonyl group, N-Eicosyl, n-docosyl, n-docosyl, n-tetracosyl, n-tetracosyl, n-pentadecyl, n-di Cetyl, n-hexadecyl, n-octadecyl, n-dodecyl, or n-dodecyl. The C ₁ -C ₁₈ -alkoxy group in the specification of the present invention represents an alkoxy group corresponding to the previously shown C ₁ -C ₁₈ -alkyl group. In the present specification, a C ₅ -C ₁₂ -cycloalkyl group represents a C ₅ -C ₁₂ -cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group or a ring. Indenyl, C ₆ -C ₁₄ -aryl represents a C ₆ -C ₁₄ -aryl group, such as phenyl or naphthyl, and C ₇ -C ₁₈ -aralkyl represents C ₇ -C ₁₈ aralkyl Groups such as: benzyl, o-, m-, p-tolyl, 2,3-, 2,4-, 2,5-, 2,6-,3,4-,3,5-xylene Base or 2,4,6-trimethylphenyl. In the present specification, a C ₁ -C ₄ -hydroxyalkyl group is taken to mean a C ₁ -C ₄ -alkyl group having a hydroxyl group as a substituent and a C ₁ -C ₄ -alkyl group. The group may be, for example, methyl, ethyl, n- or isopropyl, n-, iso-, di- or tri-butyl; a C ₁ -C ₅ -alkyl group is indicated Methyl, ethyl, n-propyl, n-butyl or n-amyl. The former enumerators are used as examples to illustrate the invention and should not be considered as unique.

In the present specification, the polyanion has a weight average molecular weight (M _w ) of from 2,000 to 5,000,000 g/mole, preferably from 10,000 to 1,000,000 g/mole, preferably between 40,000 g. / Moore is best with 600,000 grams / Moule.

The molecular weight of the polyanion can be determined by gel permeation chromatography (GPC). In this regard, the polymer is dissolved in a solvent (for example: chloroform or tetrahydrofuran) and passed through a GPC column. The reference standard used may be polystyrene in the same solvent. The detector used can be an ultraviolet detector or a refractive index detector.

The polyanion can be made from the corresponding monomer. The ratio of repeating units in the polymer can be determined by the ratio of the monomers used, wherein the aforementioned ratios need not be equivalent due to the different reaction rates. The polymerization can be initiated using a free radical, an anionic or cationic initiator. In addition, transition metal complexes can also be used for the initiation. The synthetic method for preparing polymers is described in the manual "Hakromolek" by H.-G. Elias Le" [macromolecule], in the first volume.

In addition to the polyanions defined in detail above, this novel complex comprises an optionally substituted polythiophene comprising a repeating unit of formula (IV)

Wherein R ⁷ and R ⁸ are each independently H, an optionally substituted C ₁ -C ₁₈ -alkyl group or an optionally substituted C ₁ -C ₁₈ -alkoxy group, or R ⁷ and R ⁸ are each an optionally substituted C ₁ -C ₈ -alkylene group, an optionally substituted C ₁ -C ₈ -alkylene group wherein one or more carbons The atom may be substituted by one or more of the same or different heteroatoms selected from O and S, preferably a C ₁ -C ₈ -dioxyalkylene group, optionally substituted C ₁ - a C ₈ -oxythioalkylene group or an optionally substituted C ₁ -C ₈ -dithiaalkylene group, or an optionally substituted C ₁ -C ₈ -alkylene group At least one carbon atom of the group may be optionally substituted with a hetero atom selected from O and S.

In a preferred embodiment, the polythiophene comprising the repeating unit of formula (IV) is those comprising a repeating unit of formula (IV-a) and/or formula (IV-b)

Wherein A is an optionally substituted C ₁ -C ₅ -alkylene group, preferably an optionally substituted C ₂ -C ₃ -alkylene group, and Y is O or S, R is a linear or branched, optionally substituted C ₁ -C ₁₈ -alkyl group, preferably a linear or branched, optionally substituted C ₁ -C ₁₄ -alkyl group, one Optionally substituted C ₅ -C ₁₂ -cycloalkyl group, an optionally substituted C ₆ -C ₁₄ -aryl group, an optionally substituted C ₇ -C ₁₈ -aralkyl a radical, an optionally substituted C ₁ -C ₄ -hydroxyalkyl group, or a monohydroxy group, y is an integer from 0 to 8, preferably 0, 1 or 2, 0 or 1 is more preferred, and in the case where a plurality of R groups are bonded to A, they may be the same or different.

The general formula (IV-a) should be understood that the substituent R can be bonded to the alkylene group A y times.

In another preferred embodiment, the polythiophene comprising a repeating unit of the formula (IV) is those comprising a repeating unit of the formula (IV-aa) and/or (IV-ab)

Wherein R and y are each as defined above.

In another preferred embodiment, the polythiophene comprising a repeating unit of the formula (IV) is those comprising a polythiophene of the formula (IV-aaa) and/or (IV-aba).

In the present specification, the prefix "poly-" should be understood to mean that more than one identical or different repeating unit is present in the polythiophene. The polythiophene comprises a total of n repeating units of the formula (IV), wherein n may be an integer from 2 to 2,000, preferably from 2 to 100. In the polythiophene, the repeating units of the formula (IV) may each be the same or different. Preferably, in each case, the polythiophene comprises the same repeating unit of formula (IV).

Preferably, the polythiophenes each have H on the terminal group.

In a particularly preferred embodiment, the polythiophene having a repeating unit of the formula (I) is poly(3,4-extended ethyldioxythiophene), poly(3,4-extended ethyloxythiophene), Or poly(thieno[3,4-b]thiophene), that is, a homopolythiophene comprising a repeating unit of the formula (IV-aaa), (IV-aba) or (IV-b).

In another particularly preferred embodiment, the polythiophene having a repeating unit of the formula (IV) is a copolymer comprising the formulae (IV-aaa) and (IV-aba), (IV-aaa) and Repetitive units of (IV-b), (IV-aba) and (IV-b), or (IV-aaa), (IV-aba) and (IV-b), preferably having the formula (IV- Copolymer of aaa) with (IV-aba), and (IV-aaa) and (IV-b) repeating units.

In the present specification, C ₁ -C ₅ - alkoxy extension A is methylene group, stretch ethyl, n - propyl stretched, n - butyl stretch, or n - pentyl extension; and further C ₁ The -C ₈ -alkylene group is a n-hexyl group, a n-heptyl group and a n-exetylene group. In the present specification, C ₁ -C ₈ - alkylene group is a front diagram of C ₁ -C ₈ alkyl group extends, which comprises at least one double bond. In the present specification, a C ₁ -C ₈ -dioxyalkylene group, a C ₁ -C ₈ -oxythioalkylene group and a C ₁ -C ₈ -dithiaalkylene group are: C _{a 1-} C ₈ -dioxyalkylene group, a C ₁ -C ₈ -oxythioalkylene group, and a C ₁ -C ₈ -dithiaalkylene group corresponding to C ₁ - C ₈ - alkylene group. C ₁ -C ₁₈ -alkyl, C ₅ -C ₁₂ -cycloalkyl, C ₆ -C ₁₄ -aryl, C ₇ -C ₁₈ -aralkyl, C ₁ -C ₁₈ -alkoxy and C ₁ -C ₄ -Hydroxyalkyl is as defined above. The former is used as an example to illustrate the invention and should not be considered as unique.

Other possible substituents for the aforementioned groups include a number of organic groups such as alkyl, cycloalkyl, aryl, halogen, ether, thioether, disulfide, sulfonium, sulfonium, sulfonate, amine, aldehyde A ketone, a carboxylic acid ester, a carboxylic acid, a carbonate, a carboxylate, a cyano group, an alkyl decane, and an alkoxyalkyl group, and a carboxamide group.

Monomer precursors for the preparation of polythiophenes of the formula (IV) and derivatives thereof, the preparation of which is well known to those of ordinary skill in the art, are described, for example, in L. Groenendaal, F. Jonas, D. .Freitag, H. Pielartzik and JR Reynolds, Adv. Mater. 12 (2000), pp. 481-494, and the literature cited therein.

In the present specification, derivatives of the aforementioned thiophene are meant to mean, for example, dimers or trimers of these thiophenes. Higher molecular weight derivatives, that is, tetramers of monomer precursors, pentamers, etc., may also be derivatives. These derivatives may be formed from the same or different monomer units and may be used in pure form or in a mixture with one another and/or with the aforementioned thiophenes. In the present specification, the oxidized or reduced form of these thiophene and thiophene derivatives is also included in the term "thiophene and thiophene derivatives", and the polymerization proceeds to be the same as in the case of the previously shown thiophene and thiophene derivatives. Conductive polymer.

The dispersion or solution may additionally comprise at least one polymeric binder. Suitable binders are polymeric organic binders such as polyvinyl alcohols, polyvinylpyrrolidone, polyvinyl chloride, polyvinyl acetate, polyvinyl butyrate, polyacrylates, Polyacrylamide, polymethacrylate, polymethacrylamide, polyacrylonitrile, styrene/acrylate, vinyl acetate/acrylate and ethylene/vinyl acetate copolymer, polybutadiene, polyiso Pentadiene, polystyrene, polyether, polyester, polycarbonate, polyurethane, polyamide, polyimine, polyfluorene, melamine-formaldehyde resin, epoxy resin, polyoxyl Resin, or cellulose.

The optionally substituted polythiophene is cationic, and "cationic" refers only to the charge on the polythiophene backbone. The polythiophene may have a positive and a negative charge in the structural unit depending on the substituent on the R group. In this case, the positive charge is on the polythiophene backbone and the negative charge may be on the sulfonate or carboxylate group. The group is substituted on the R group. In this case, the positive charge of the polythiophene backbone can be partially or completely saturated by any anionic group present on the R group. Overall, the polythiophenes in these cases may be cationic, uncharged, or even anionic. However, in the present specification, they are all regarded as cationic polythiophenes because the positive charge on the polythiophene backbone is critical. The positive charge in the formula is not shown because its exact number and position cannot be accurately stated. However, the number of positive charges is at least 1 and at most n, where n is the total number of all repeating units (identical or different) within the polythiophene.

The inventive polythiophene/polyanion complex can be dissolved or dispersed in a water-immiscible solvent. Suitable solvents include, in particular, the following organic solvents which are inert under the reaction conditions: aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane, heptane and cyclohexane; aliphatic Carboxylic acid esters such as ethyl acetate; chlorohydrocarbons such as dichloromethane and dichloroethane; aliphatic and araliphatic ethers such as diethyl ether or tetrahydrofuran. Particularly preferred are aliphatic and aromatic hydrocarbons.

The optionally substituted polythiophene of the formula (IV) can be obtained by oxidative polymerization of an optionally substituted thiophene of the formula (V)

Wherein R ⁷ and R ^{8 are} each as defined above.

The preferred field for the optionally substituted thiophene of formula (V) is the same as the optionally substituted polythiophene of formula (IV).

For this oxidative polymerization, an oxidizing agent suitable for the oxidative polymerization of thiophene can be used, and it is known to those having ordinary knowledge in the art, as described in, for example, Journal of the American Chemical Society, No. 85, p. 454 ( 1963). In the present specification, the oxidizing agent used may be H ₂ O ₂ , K ₂ C ₂ O ₇ , alkali metals and ammonium peroxodisulfate, for example: sodium or potassium peroxydisulfate, alkali metal perborate, Potassium permanganate, copper salt, for example: copper tetrafluoroborate, or cerium (IV) salt or CeO ₂ . Preferred are oxidizing agents which are inexpensive and easy to handle, such as iron (III) salts of inorganic acids, such as FeCl ₃ , Fe(ClO ₄ ) ₃ , and irons of organic acids and inorganic acids having organic groups ( III) Salts.

An iron (III) salt of an inorganic acid having an organic group, and examples thereof include: an iron (III) salt of a sulfuric acid monoester of a C ₁ -C ₂₀ -alkanol, for example, iron (III) of lauryl sulfate salt. Examples of iron (III) salts of organic acids include: iron (III) salts of the following: C ₁ -C ₂₀ -alkanesulphonic acid, such as methane- and dodecanesulfonic acid, aliphatic C _{a 1-} C ₂₀ -carboxylic acid such as 2-ethylhexylcarboxylic acid, an aliphatic perfluorocarboxylic acid such as trifluoroacetic acid, and perfluorooctanoic acid, an aliphatic dicarboxylic acid such as oxalic acid, and especially An aromatic sulfonic acid substituted with a C ₁ -C ₂₀ -alkyl group, such as: benzenesulfonic acid, p-toluenesulfonic acid, and dodecylbenzenesulfonic acid, and naphthenic acid, such as camphorsulfonate acid.

In the present specification, a C ₁ -C ₂₀ -alkanol represents a monohydric alcohol having an alkyl group of 1 to 20 carbon atoms, C ₁ -C ₂₀ -alkanesulfonic acid. Represents a monobasic sulfonic acid having an alkyl group of 1 to 20 carbon atoms, and a C ₁ -C ₂₀ -carboxylic acid representing a monobasic carboxylic acid having from 1 to 20 carbon atoms Alkyl group.

It has now surprisingly been found that for the polymerization of the optionally substituted thiophene of the formula (V), in the reaction medium, ie the non-polar solvent, it is only necessary to use a low solubility oxidizing agent, for example: iron toluenesulfonate. (III) substantially insoluble in toluene. However, EDT can be polymerized by iron (III) toluene in toluene to give PEDT.

The invention therefore further provides a process for the preparation of an optionally substituted polythiophene of the formula (IV) in the presence of a polyanion characterized by an oxidative polymerization of the optionally substituted thiophene of the formula (V) In a non-polar solvent,

An oxidizing agent selected from the group of the aforementioned iron (III) salts is used in an amount of from 0.5 to 10 moles per mole, preferably from 1 to 3 moles per mole, and R ⁷ and R ^{8 are} each as defined above. .

Preferred oxidizing agents are iron (III) salts of aliphatic and aromatic sulfonic acids, more preferably iron (III) p-toluenesulfonate. A particularly preferred molar ratio is 1 to 3 moles of iron (III) toluenesulfonate per mole of thiophene. The solvent used may be a water-immiscible solvent as indicated above.

In the present specification, a mixture of the above-mentioned iron (III) salts of organic acids can be used. The aforementioned iron (III) salts may be optionally used as a catalyst together with other oxidizing agents. For the oxidative polymerization of the optionally substituted thiophene of formula (V), theoretically, 2.25 equivalents of oxidant per thiophene are required (see, for example, Polymer Science Journal, Part A, Polymer Chemistry, No. 26, p. 1287 (1988)). However, higher or lower equivalent oxidants can also be used.

The invention further provides a copolymer comprising at least a repeating unit of the formulae (IIa) and (III)

Wherein R ⁵ is H or an optionally substituted C ₁ -C ₁₈ -alkyl group, preferably H, R ⁶ is H or an optionally substituted C ₁ -C ₃₀ -alkyl group a group, preferably an optionally substituted C ₁ -C ₂₀ -alkyl group, preferably an optionally substituted C ₁ -C ₁₂ -alkyl group, and a repeating unit ( The mass ratio of IIa) is between 2% and 80%, preferably between 2% and 50%, and the mass ratio of the repeating unit (III) is between 5% and 98%. It is preferably between 50% and 98%.

The C ₁ -C ₁₈ -alkyl groups shown here and the C ₁ -C ₃₀ -alkyl groups shown are defined to correspond to the definitions of the aforementioned alkyl groups.

The repeating units of the formulae (IIa) and (III) in the copolymer may be individually the same or different. Preferably, the copolymers in the individual cases have the same repeating units of the formulae (IIa) and (III).

In the present specification, the inventive copolymer has a molecular weight of from 2,000 to 5,000,000 g/mole, preferably from 10,000 to 1,000,000 g/mole, preferably between 40,000 and 600,000 g. / Moor is the best between.

The mass ratio of the repeating units of the general formulae (IIa) and (III) was compared by elemental analysis and ¹ H NMR. In the elemental analysis, the calculated and found percentages are compared. The characteristic signals of the special repeating units were compared with each other in the ¹ H NMR spectrum.

The inventive copolymer can be dissolved or dispersed in a water-immiscible solvent. Suitable solvents are the solvents indicated above, and preferred solvents are aromatic or aliphatic hydrocarbons.

The invention further provides for the use of the inventive complexes for the manufacture of electrically conductive films or coating systems, or for use as hole injection layers in organic light-emitting diodes.

The following examples are merely illustrative of the invention and are not to be construed as limiting.

Instance Example 1: Synthesis of 4-dodecylacetophenone

Aluminium chloride (227.114 grams = 1.7 moles) was suspended in dichloromethane (800 mL) under argon and cooled to 0 °C. Acetic anhydride (89.872 g = 0.88 mol) dissolved in 100 ml of dichloromethane was slowly added dropwise thereto over 30 minutes (min.). The mixture was continuously stirred for about 15 minutes, and then, under cooling, dodecylbenzene (99.267 g = 0.4 mol) dissolved in CH ₂ Cl ₂ (at 0 ° C) was added dropwise over 30 minutes. This reaction was further stirred overnight without cooling. The obtained orange reaction solution was slowly poured onto 1.5 liters of crushed ice and separated from the aqueous phase, and the aqueous phase was discarded. The organic phase was extracted and shaken twice by using each of 500 ml: about 10% hydrochloric acid, saturated sodium carbonate solution and saturated sodium chloride solution. The organic phase was dried over anhydrous magnesium sulfate and the solvent was removed using a rotary evaporator. The obtained brown solid was recrystallized from methanol. The crystallization was achieved after 4 overnight at 4 °C. Yield: 106.669 grams = 0.37 moles = 92.4% of theory: analysis: 250 MHz, CDCl ₃ ; δ = 0.90 (dd, 3H, J = 5.7, 6.9 Hz), 1.28 (m, 18H), 1.56-1.60 ( m, 2H), 2.61 (s, 3H), 2.65 (t, 2H, J = 7.3 Hz), 7.27 (d, 2H, J = 8.2 Hz), 7.89 (d, 2H, J = 8.2 Hz).

Example 2: Synthesis of (p-dodecylphenyl)methylmethanol

4-Dodecylacetophenone (106.669 grams = 0.37 moles) was initially added to methanol (1.1 liters) and cooled to 0 °C under argon. A total of 10 parts of NaBH ₄ (20.39 g = 0.54 mol) was added to this solution at 5 minute intervals. After the gas evolution was relieved, the ice bath was removed and the reaction was stirred further overnight at room temperature. The solution was concentrated to dryness and the white crystal residue was taken to 1 liter hexane. The suspension obtained by extraction was shaken twice by using 500 ml each time: about 10% hydrochloric acid, which completely dissolved the remaining solid. The organic phase was extracted by shaking twice with 500 ml of a saturated sodium chloride solution, dried over magnesium sulfate, filtered, and then concentrated on a rotary evaporator and crystallised at -20 °C. The crystals were filtered and dried.

Yield: 100.032 grams = 0.35 moles = 93.4% of theory: analysis: 250 MHz, CDCl ₃ ; δ = 0.90 (dd, 3H, J = 5.4, 6.9 Hz), 1.20-1.35 (m, 18H), 1.51 (d) , 3H, J = 6.3 Hz), 1.54-1.65 (m, 2H), 1.81 (d, 1H, J = 1.9 Hz), 2.60 (t, 2H, J = 7.9 Hz), 4.86 (m, 1H), 7.20 (d, 2H, J = 7.9 Hz), 7.31 (d, 2H, J = 7.9 Hz).

Example 3: Synthesis of p-dodecylstyrene

1.2 liters of toluene was initially charged in a 2 liter round bottom flask equipped with a water separator and a reflux condenser, followed by addition of (p-dodecylphenyl)methylmethanol (50.082 g = 0.173 mol) and Monohydrate p-toluenesulfonic acid (0.679 g = 3.6 mmol). The mixture was heated to reflux with constant stirring and the boiling was maintained until no more water was separated. Once the reaction mixture was cooled to room temperature, the organic phase was extracted by shaking twice with 500 ml of water each time and shaking once with 250 ml of saturated sodium chloride solution. After drying with magnesium sulfate, the solvent was removed using a rotary evaporator. Get a butter. Thereafter two batches were combined. The crude product was purified by column chromatography on 400 g of hydrazine gel 60 using hexane as the eluent, and a fraction of 100 ml was selected.

R _f (methanol) = 0 (hexane)

R _f (by-product) = 0.70 (hexane)

R _f (n-dodecylstyrene) = 0.50 (hexane)

Yield: 97.934 g = 0.36 Mo Er analysis: 250 MHz, CDCl ₃ ; δ = 0.90 (t, 3H, J = 6.6 Hz), 1.20-1.4 (m, 18H), 1.60 (m, 2H), 2.60 (t, 2H, J=7.55 Hz), 5.22 (d, 1H, J = 7.85 Hz), 5.73 (d, 1H, J = 17.6 Hz), 6.71 (q, 1H), 7.15 (d, 2H, J = 8.0 Hz) , 7.35 (d, 2H, J = 7.9 Hz).

Example 4: Synthesis of silver salt of p-styrenesulfonic acid

400 ml of water was initially charged in a 500 ml round bottom flask, and 45.046 g of sodium p-styrenesulfonate (45.046 g = 0.200 mol) was dissolved therein with stirring at room temperature (RT). To ensure no light, the outer periphery of the flask was wrapped in aluminum foil. The solution was cooled to 0 ° C and blended in portions with 34.225 grams of silver nitrate (34.225 grams = 0.200 moles) which then produced a pink precipitate. All subsequent operations are performed as far as possible from light. The mixture was stirred at 0 ° C for an additional 30 minutes and the solid was filtered off with a D2 glass frit. The obtained filter cake was washed in three portions with 150 ml of ice water, and repeatedly dried into a slurry using a small amount of diethyl ether. The beige solid was added to 500 ml of acetonitrile and the undissolved solid was filtered off through a D4 glass frit. The solution was concentrated to dryness and the solid obtained was stored in a freezer overnight. Yield: 47.890 g = 0.165 mol = 82.5% of theory.

Example 5: Synthesis of ethyl p-styrenesulfonate

A 250 ml round bottom flask wrapped in aluminum foil was initially charged with 47.890 grams of silver styrene-4-sulfonate (47.890 grams = 0.165 moles) in 390 ml of acetonitrile and stirred with a large stirrer. Blended with 35.77 grams of ethyl bromide (35.77 grams = 0.33 moles). An identical aluminum foil wrapped reflux condenser was attached to the flask which was supplied with a balloon filled with argon. The reaction mixture was stirred at 70 ° C for 5 hours (h), and after cooling to room temperature, the formed silver bromide was filtered off through a D4 glass frit and the filtrate was concentrated using a rotary evaporator. The remaining oil was added to 400 ml of dichloromethane (DCM) and filtered through a D4 glass frit with a 5 cm sorghum gel layer. The material obtained by filtration was repeatedly extracted with 50 ml of DCM each time, and the solvent was removed. A yellow very high viscosity oil is obtained.

Yield: 29.457 gram = 0.139 mole = 84.2% of theory: analysis: 250 MHz, CDCl ₃ ; δ = 1.30 (t, 3H, J = 7.3 Hz), 4.12 (q, 2H, J = 7.3 Hz), 5.46 ( d, 1H, J = 11.1 Hz), 5.96 (d, 1H, J = 17.7 Hz), 6.77 (dd, 1H, J = 11.1, 17.4 Hz), 7.65 (d, 2H, J = 8.2 Hz), 7.86 ( d, 2H, J = 8.2 Hz).

Example 6: Synthesis of poly(ethyl p-styrenesulfonate-co-p-dodecylstyrene)

Dichloroethane (250 g) was initially charged as a solvent in a 500 ml flask under an argon atmosphere. Add 35.0 grams of p-dodecylstyrene (35.0 grams = 128.45 millimoles; its preparation is described in Example 3) and 7.28 grams of ethyl p-styrenesulfonate (7.28 grams = 34.30 millimoles; preparation of the description After Example 5), the mixture was saturated with argon by a gas inlet tube. For this, argon gas was continuously passed through the mixture for 15 minutes. During this time, the mixture was heated to 60 °C. The free radical initiator used was azobisisobutyronitrile (AIBN) which was saturated with argon and dissolved in some dichloroethane and added through a septum. The polymerization reaction solution was further purged with argon gas for 5 minutes, and then the polymerization was completed overnight at 60 °C. After the slightly viscous polymerization solution was cooled, the polymer was precipitated in methanol under stirring. The polymer obtained after precipitation was redissolved in tetrahydrofuran (THF) and precipitated again in methanol. The separated white polymer was dried under high vacuum.

Yield: 18 g = 42.6% (GPC) analysis theoretical value: molecular weight (relative to the tetrahydrofuran, the PS): 120000 g / mole, a polydispersity _{D (M w / M n)} : 1.5 analysis (NMR): 250MHz, CDCl ₃ ; δ = 0.88 (3H), 1.20 - 1.30 (-CH2-, -CH-), 1.40-1.45 (3H, CH3 ester), 1.45-1.55 (2H), 2.50-2.60 (2H), 4.0 -4.1 (2H, CH2-ester), 6.0-7.0 (4H), 7.3-7.6 (4H, -CH-ester)

The degree of sulfonation may be used spectral analysis NMR, for this, the peak at 0.88 ppm (twelve groups of the terminal CH _3), and 4.0-4.1 ppm (ethyl ester of CH ₂₎ are considered related to each other. This resulted in an integral calibrated ratio of dodecyl styrene to ethyl styrene sulfonate of 1:5.6, which corresponds to a degree of sulfonation of the polymer of 21.09%.

Analysis - Elemental Analysis (EA):

This resulted in a degree of sulfonation of 18.77%.

The resulting degree of sulfonation is:

Example 7 (Invention): Synthesis of poly(p-styrenesulfonic acid-co-p-dodecylstyrene)

15.0 g of poly(ethyl-p-styrenesulfonate-co-p-dodecylstyrene) (prepared as described in Example 6) was dissolved in 50 ml of dichloromethane and 100 ml of toluene and heated. To 100 ° C. During heating, the solution was degassed with argon. 60 grams of trimethyldecyl bromide (TMSBr) (60 grams = 16.33 millimoles) was added via a septum over a 5 minute period. The yellow solution was stirred at 100 ° C under reflux for 60 hours, then concentrated, and the polymer was precipitated from methanol / water. The polymer obtained after precipitation was redissolved in tetrahydrofuran (THF) and precipitated in methanol. The separated yellow polymer was dried under high vacuum.

Yield: 10 grams of analysis (EA):

This resulted in a degree of sulfonation of 20.8% (calculated as complete hydrolysis).

Analysis (NMR): 250 MHz, CDCl ₃ ; δ = 0.88 (3H), 1.20-1.40 (-CH ₂ -, -CH-), 1.45-1.55 (2H), 2.50-2.60 (2H), 6.0-7.0 (4H) ), 7.3-7.6 (-CH-aromatic ester)

The degree of hydrolysis of the ester can be determined by NMR spectroscopy, for which a peak at 0.88 ppm (terminal CH _{3 of the} dodecyl group) and a peak at 4.11 ppm (CH _{2 of the} ethyl ester) are barely identifiable and Think of each other (1:53.3). This resulted in a degree of hydrolysis of the ester of about 86.7%.

Analysis (GPC):

The sample was dissolved in tetrahydrofuran. The calibration standard used was polystyrene. The detectors used are ultraviolet detectors and refractive index detectors (RIs).

Example 8 (Invention): Synthesis of poly(3,4-extended ethyldioxythiophene/poly(p-styrenesulfonic acid-co-p-dodecylstyrene) complex

12.5 grams of toluene and 1 gram of poly(p-styrenesulfonate-co-p-dodecylstyrene) from Example 7 were initially charged in a 50 ml round bottom flask and stirred for 10 minutes. Subsequently, 0.3 g (2.1 mmol) of ethylene dioxythiophene (Clevios M V2, H. C. Starck GmbH) was added. Thereafter, 1.33 g of iron (III) tosylate (2.3 mmol) was added, and the mixture was stirred at room temperature for 24 hours. Thereafter, the stirrer was turned off, and after 10 minutes, the resulting dispersion was decanted. After a further 48 hours, the mixture was filtered through a filter having a pore size of 0.45 microns.

Analysis: solid content

The solid content was determined, and 2 g of the sample was dried at 100 ° C for 16 hours. The solid content was determined to be 8.11% using the starting weight and the dry content.

Example 9 (Invention): Determination of Specific Resistivity and Use of Complexes in OLEDs

The inventive formulation of the poly(3,4-extended ethyldioxythiophene/poly(p-styrenesulfonate-co-p-dodecylstyrene) complex from Example 8 was used to construct an organic Light-emitting diode (OLED). The procedure for manufacturing OLED is as follows:

Preparation of ITO-coated substrate (ITO = indium tin oxide)

ITO-coated glass (Merck Balzers AG, FL, Part. No. 253674 XO) was cut into 50 mm x 50 mm pieces (substrate). The substrate was then washed in an ultrasonic bath of 3% aqueous Mucasol solution for 15 minutes. These substrates were then rinsed with distilled water and spin dried in a centrifuge. This rinsing and drying operation was repeated 10 times. Immediately prior to coating, the ITO-coated side was rinsed in an ultraviolet/ozone reactor (PR-100, UVP, Cambridge, UK) for 10 minutes.

Applying a hole-injection layer

About 5 ml of the inventive dispersion from Example 8 was filtered (Millipore HV, 0.45 micron). The washed ITO-coated substrate was placed on a spin coater and the filtered solution was distributed over the ITO-coated side of the substrate. The plate was then rotated at 1500 rpm for 30 seconds. The coated substrate was then dried on a hot plate at 130 ° C for 15 minutes. The layer thickness is 500 nm (Tencor, Alphastep 500).

All other operating steps were carried out in a pure N ₂ atmosphere (inert gas glove box system, M. Braun, Garching) and the coated substrate was transferred into it. First, the substrate coated with the dispersion of Example 8 was dried on a hot plate at 180 ° C for 5 minutes. The conductivity of the dispersion from Example 8 was measured on individual layers and applied by a shadow mask to a 2.5 cm length Ag electrode of 2.5 cm (similar to operation 4). The surface resistivity measured by an electrometer is multiplied by the layer thickness to obtain the specific resistivity of electricity. These layers have a specific resistivity of approximately 100 000 000 ohms. Centimeters.

Applying an emissive layer

A solution of 5 ml of a 1% by weight xylene solution of a white polymeric emitter was filtered (Millipore HV, 0.45 μm) and distributed on the dried hole injection layer. The plate was then rotated at 2500 rpm and the lid was closed and the emitter's supernatant solution was spun off for 30 seconds. The layer was then dried on a hot plate at 180 ° C for 10 minutes. The total layer thickness is 585 nm.

Applying a metal cathode

A metal electrode was applied as the cathode of the emissive layer. In this regard, the substrate was placed with the emissive layer facing down on a shadow mask containing a 2.5 mm diameter hole. From two steam deposition vessels with a pressure of p = 10-3 Pa, a 5 nm thick Ba layer and a 200 nm thick Ag layer were successively applied by vapor deposition. The vapor deposition rate is 10 for 钡 /second and for silver 20 /second. The separated metal electrode has an area of 4.9 mm ² .

OLED characteristics

The two electrodes of the organic LED are (contact-) connected to a voltage source via electrical leads. The positive electrode is connected to the ITO electrode, and the negative electrode is connected to the metal electrode via a thin flexible Au wire. The dependence of the OLED current and electroluminescence intensity (this uses a photodiode detection (EG&G C30809E)) on the voltage is recorded. The service life is then determined by passing a fixed current I = 60 microamperes through the device and monitoring the voltage and light intensity as a function of time.

result

Thus, the resulting OLED exhibits the diode properties of a typical organic light-emitting diode (see Figure 1). When a voltage of 12 volts U is applied, the forward current I is 0.57 amps/cm 2 and the luminance L is 9.2 cd/m 2 . The lifetime defined as one-half of the luminescence decay to the initial luminance is 60 hours, and a fixed diode current is 60 microamperes.

Thus, the basic applicability of the anhydrous PEDOT-containing solution based on the inventive dispersion of Example 8 was confirmed.

Figure 1 shows the diode performance of a typical organic light-emitting diode in the OLED produced.

Claims (10)

A complex comprising an optionally substituted polythiophene and a polyanion, characterized in that the polyanion comprises a copolymer having repeating units of the formulae (I) and (III), or a formula Repeating units of (II) and (III), or repeating units of formula (I), (II) and (III): Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ are each independently H, an optionally substituted C ₁ -C ₁₈ -alkyl group, and an optionally substituted C ₁ -C _{An 18} -alkoxy group, an optionally substituted C ₅ -C ₁₂ -cycloalkyl group, an optionally substituted C ₆ -C ₁₄ -aryl group, optionally Substituting a C ₇ -C ₁₈ -aralkyl group, an optionally substituted C ₁ -C ₄ -hydroxyalkyl group or a hydroxyl group, R ⁶ is an optionally substituted C ₁ - a C ₃₀ -alkyl group, D is a direct covalent bond or an optionally substituted C ₁ -C ₅ -alkylene group, R is a linear or branched, optionally substituted C ₁ a -C ₁₈ -alkyl group, an optionally substituted C ₅ -C ₁₂ -cycloalkyl group, an optionally substituted C ₆ -C ₁₄ -aryl group, optionally a substituted C ₇ -C ₁₈ -aralkyl group, an optionally substituted C ₁ -C ₄ -hydroxyalkyl group or a monohydroxy group, x is an integer from 0 to 4, M Is H, or Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , NH ₄ ⁺ , Na ⁺ , K ⁺ , or other cations, wherein the ratio of the repeating units (I) to (II) is between 0 and 5 Between 0% by mass and the ratio of the repeating unit (III) is between 20 and 100% by mass, and wherein the ratio of the repeating units (I) to (II) must be 0% by mass. A complex according to the first aspect of the patent application, characterized in that the polyanion is a copolymer of repeating units of the formulae (II) and (III). A complex according to claim 2, characterized in that the polyanion comprises a copolymer of repeating units of the formulae (IIa) and (III) Wherein R ⁵ is H or an optionally substituted C ₁ -C ₁₈ -alkyl group, and R ⁶ is an optionally substituted C ₁ -C ₃₀ -alkyl group. The complex according to any one of claims 1 to 3, characterized in that the molecular weight of the polyanion is between 2,000 and 5,000,000 g/mole. The complex according to any one of claims 1 to 3, characterized in that the optionally substituted polythiophene comprises a repeating unit of the formula (IV) Wherein R ⁷ and R ⁸ are each independently H, an optionally substituted C ₁ -C ₁₈ -alkyl group or an optionally substituted C ₁ -C ₁₈ -alkoxy group, or R ⁷ and R ⁸ are each an optionally substituted C ₁ -C ₈ -alkylene group, wherein one or more carbon atoms may be selected from one or more of the same or different selected from O and S. Substituted by a hetero atom, preferably a C ₁ -C ₈ -dioxyalkylene group, an optionally substituted C ₁ -C ₈ -oxythioalkylene group or an optionally substituted a C ₁ -C ₈ -dithiaalkylene group, or an optionally substituted C ₁ -C ₈ -alkylene group, wherein at least one carbon atom may be optionally selected from O and S The hetero atom is substituted. The complex according to any one of claims 1 to 3, characterized in that the optionally substituted polythiophene comprises a repeat of the formula (IV-aaa) and/or the formula (IV-aba) unit The complex according to any one of claims 1 to 3, characterized in that the complex is soluble or dispersible in a water-immiscible solvent selected from aromatic and aliphatic hydrocarbons. A group consisting of aliphatic carboxylic acid esters, chlorocarbon hydrocarbons, aliphatic or araliphatic ethers. a copolymer characterized in that it comprises at least a repeating unit of the formulae (IIa) and (III) Wherein R ⁵ is H or an optionally substituted C ₁ -C ₁₈ -alkyl group, R ⁶ is an optionally substituted C ₁ -C ₃₀ -alkyl group, and the repeating unit (IIa The mass ratio is between 2% and 80%, and the mass ratio of the repeating unit (III) is between 20% and 98%. A process for the preparation of a complex according to any one of claims 1 to 3 in the presence of a polyanion, characterized in that the oxidation of the optionally substituted thiophene of the formula (V) is carried out using an oxidizing agent Polymerization The thiophene and the oxidizing agent are used in a molar ratio of from 0.5 to 10, in a non-polar solvent, and wherein R ⁷ and R ^{8 are} the same as defined in claim 5 of the scope of the patent application. Use of a complex according to any one of claims 1 to 3 for the production of a conductive film or coating system or as a hole injection layer in an organic light-emitting diode.